Improvement in steam-boilers



UNITED STATES PATENT OFFICE.

BENJAMIN L. GRIFFITH, OF IIAZLE TOVNSHIP, PENNSYLVANIA.

IMPROVEMENT IN STEAM-BOILERS.

Speciiication forming part of Letters Patent No. 24,117, dated May 24, 1859.

To all whom it may concern:

Be it known that l, BENJAMIN L. GRIFFITH, of Hazle township, in the county of Luzerne, in the State of Pennsylvania, have invented a new and useful Improvementin the Construction of Steam-Boilers; and I do hereby declare that the following is afull and exact description thereof, reference being had to the accompanying drawings, and to the letters of reference marked thereon- Figure l being an exterior view of the boiler; Fig. 2, a vertical longitudinal section through the center line of boiler.

The nature of 'my invention consists in the arrangement of the smoke-stack N, the chamber F, the two series of iiues IVI M, and the doors U U and diaphragms K K.

To enable others skilled in the art to make and use my invention, I will proceed to describe its construction and operation.

The top 1of the exterior shell is made the same as those known as the wagon-top boiler. The sides can either be made vertical or inclined. The lower portion of the fire-box forms an oblong square, and can extend the whole or only a part of the length of the boiler. There is a steam-dome situated upon the top of the boiler and midway between the ends. Through this steamdome the smoke-stack passes and projects beyond the top. Each end of the boiler is provided with two doors. Through the upper one access is had to the iiues, and through the lower one fuel is passed to the lire. The sides of the interior furnace or fire-box are constructed parallel with the exterior sides as high as the center line of flue-sheets B B, where they are connected to the convex crown-sheet D, leaving sufficient space between the exterior and interior sides for t-he circulation of water. The fine-sheets B B are of a circular form, and are secured to the con- Vex crown-sheet D a sufficient distance from the ends C C to allow the iiues to be secured in their proper place. In those spaces between the flue-sheets B B and the ends C C the sides of the fire-box are continued up to the top and concentric with said flue-sheets, to which they are attached. The said sides are also connected to the ends C C, which are parallel with the exterior ends, and are continued up as high as the top of flue-sheets B B, and are A concentric therewith at their upper ends.

F is a cylindrical or other suitably formed chamber, in which are secured a flue sheet or sheets corresponding with flue-sheets B B. The said chamber is situated between the said flue-sheets in such a position asto receive the opposite ends of the flues which are secured in the due-sheets B B. Vhen only one iiuesheet is used in said chamber, it is intended to bend the flues up at their ends corresponding thereto. There should be ample space left between the chamber F and crown-sheet D for the circulation of water between the two series of flues. The smoke-stack N is secured to the top of chamber F and passes through the steam-dome H, to the top of which it is secured in such a way as will prevent the escape of steam.

To the ends C C are attached water-space proj ectons or diaphragms K K, extending into the furnace directly beneath the crown-sheet D, for the purpose of equalizing the draft over the interior of the furnace, and also to form a shelf or jamb for the doors U U. There should be ample space left between the crownsheet D and the diaphragms K K for the passage of the products of combustion. Upon the upper side of said diaphragms are placed doors U U, for the purpose of closing the communication between the ilues and furnace and alternating the passage of the products of combustion through both series of lues. The said doors U U are made hollow, and are secured to and revolve with a hollow shaft that communicates with the exterior of the boiler for the purpose of admitting air to the gases evolved from the fuel through said hollow shaft and small perforat-ions made in their sides. The admission of air can be controlled by valves fixed on the end of said hollowy shafts. The said doors can be operated by a lever secured to the end of said hollow shafts. Itis, however, contemplated,in cases where the iire is so intense as to destroy the said doors U U when used as air-distributers, to construct them hollow without perforations, and connect them to the adjacent Water-spaces of the boiler by means of hollow hinges, and thereby secure a circulation of water through them and prevent their rapid destruction by the fire; and in such case it is contemplated to admit the air to the gases evolved from the fuel through hollow stay-bolts in the sides and ends of the furnace.

The advantages possessed by the withindescribed arrangement are as follows:

First. By the position of the chamber F and its direct communication with the smokestack N there is a draft created through both series of tlues and in opposite directions, thereby bringing the entire Hue-surface into closer proximity to the glowing fuel than the usual Way of construct-ing horizontal iue or tubular boilers, for in the usual way of making such boilers the products of combustion are caused to enter the tlues at one end of the boiler and are discharged therefrom at the opposite end of the boiler, hence making that portion of the flue from which the products of combustion are discharged at too great a distance from the fire. This arrangement also increases the heating-surfaces of the boiler by bringing both ends of the boiler in direct contact with the products of combustion.

Second. By means of the doors U U the draft can be alternated through both series of iiues,

and thereby causing the-gases evolved from the fuel in one end of the furnace, after becoming thoroughly mixed with the air which is admitted through the hollow shaft and perforations in said doors or hollow stay-bolts in the sides and ends of the furnace, to pass over the glowing fuel in the opposite end of the furnace, and in so doing will become ignited immediately under the crown-sheet D before entering the tlues, hence securing the perfect ignition of all the combustible elements of the fuel; and when the fuel in both ends of the furnace becomes thoroughly ignited both of the said doors can be opened, and thereby create a draft through both series of iiues at the same time and in opposite directions.

I claim- The combination of the Singlesmoke-stack N, single chamber F, and double series of fines MM with the hollow hinged doors U U and diaphragms K K, arranged and constructed substantially as and for the purpose set forth.

B. L. GRIFFITH. Witnesses: JN0. C.FRU1T,

J AMES WHITAKER. 

